/usr/share/gimp/2.0/gradients/Default.ggr is in gimp-data 2.8.10-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | GIMP Gradient
Name: Default
1
0.000000 0.500000 1.000000 0.000000 0.000000 0.000000 1.000000 1.000000 1.000000 1.000000 1.000000 0 0
|